What you need to know about monkeypox
Monkeypox is a viral disease that occurs in both humans and animals. It is caused by the monkeypox virus and presents symptoms of fever, rash and swollen lymph nodes. The disease is mainly prevalent in Central and West Africa. Since May 2022, cases of monkeypox have been reported in countries where monkeypox is not usual or has not previously been reported. To protect citizens' health, we provide the following tips to describe the outbreak and prevent and control the disease.
The first human case of monkeypox was reported in 1970 in the Democratic Republic of the Congo. Since then, it has been reported in 10 other African countries. It is currently believed that the central and western regions of Africa are endemic areas for monkeypox and cases are mainly found in their tropical rainforest areas.
Regions outside of Africa are non-endemic areas with fewer monkeypox outbreaks and limited local transmission. In 2003, monkeypox occurred in the United States, which was the first time it had been found outside Africa. The United Kingdom reported a few cases in 2018, 2019 and 2021, most linked to travel to African regions.
On May 13, the United Kingdom first reported local monkeypox cases. After that, more cases have been reported in Europe, America, Asia, Oceania and Africa.
As of June 8, 1,285 confirmed cases and one probable case have been reported in 28 countries on five continents where monkeypox is not usual or had not previously been reported. Of those cases, the majority (87 percent) of confirmed cases are from the European Region (1,112 cases). Confirmed cases have also been reported in the Americas (153 cases), Asian regions (13 cases), Oceania (six cases) and African regions (one case).
Since the beginning of this year, monkeypox infections have also been reported in endemic countries in Africa. As of June 8, 1,526 confirmed cases with 72 deaths were reported in eight African countries. The Democratic Republic of the Congo reported the most cases (1,366 cases, 64 deaths), followed by Nigeria (141 cases, one death), Cameroon (31 cases, two deaths), the Central African Republic (25 cases, two deaths), Ghana (17 cases, zero deaths), the Republic of the Congo (nine cases, three deaths), Libya (four cases, zero deaths) and Sierra Leone (two cases, zero deaths).
Both the number of cases and the geographical range of the epidemic have grown rapidly. Most of the cases were young and middle-aged gay men. The spread of the epidemic is closely related to sexual activities. Most of the patients had not traveled to monkeypox endemic areas.
Basic facts about monkeypox
Monkeypox virus is an orthopoxvirus that causes a disease with symptoms similar, but less severe, to smallpox. There are two variants of the virus: the Congo Basin clade and the West African clade. Samples from monkeypox cases found in non-endemic areas since May were identified as the West African clade by sequencing analysis.
Monkeypox virus is sensitive to heat. 56 C for 30 minutes or 60 C for 10 minutes can inactivate the virus. It can also be inactivated by ultraviolet rays and general disinfectants. The virus is also sensitive to sodium hypochlorite, chloroxylenol, glutaraldehyde, formaldehyde and paraformaldehyde.
Epidemiology of monkeypox
Monkeypox virus is mainly found in African rodents. Primates (monkeys, chimpanzees, humans) that contact rodents infected with monkeypox virus could be infected as well.
Monkeypox virus invades the human body mainly through mucous membranes and broken skin. Human beings are mainly infected by contacting respiratory secretions of the animals, lesion exudate, blood and other body fluids.
Human-to-human transmission occurs through close or direct physical contact with infectious lesions or mucocutaneous sores (through face-to-face, skin-to-skin, mouth-to-mouth, mouth-to-skin transmission) including during sexual activity, respiratory droplets (and possibly short-range aerosols) or contact with contaminated materials. It is unknown whether transmission occurs through semen or vaginal secretions. Monkeypox virus can also be transmitted from a pregnant woman to her fetus via the placenta.
Vaccination against smallpox was shown in the past to be cross-protective against monkeypox. However, any immunity from smallpox vaccination will only be present in people aged 42 or older, depending on the country, since smallpox vaccination programs ended worldwide in 1980 after its eradication.
Symptoms of patients infected with monkeypox
The incubation period is between 5 to 21 days, and mostly between six to 13 days.
The early symptoms of the disease are chills and fever with body temperature mostly above 38.5 C, accompanied with headache, drowsiness, fatigue, backache and muscle aches. Most patients have swollen lymph nodes in the neck, armpit and groin.
The rashes appear in one to three days after disease onset (see image below). Rashes first appear on the face, then the arms and legs as well as other body parts. Rashes can also appear in oral mucosa, genitals, conjunctiva and corneas. A rash will progress in sequential stages – macules, papules, vesicles, pustules and scabs.
Some patients might present with complications including secondary bacterial infections, bronchopneumonia, encephalitis and corneal infection. Severe cases are more common in young children and immunocompromised people.
During the current outbreak, many infected cases outside endemic areas present mild and atypical symptoms of monkeypox associated with peri-genital and/or peri-anal distribution of rashes.
Treatment and prevention
Monkeypox is a self-limited disease with a good prognosis in most cases. At present, there is no specific anti-monkeypox virus drug in China, and symptomatic supportive treatment and treatment of complications are available.
Prevention tips for individuals
1. People who are traveling or living in outbreak countries should follow the countries’ epidemic instructions. Avoid contact with rodents and primates (including animals’ blood and meat). If you have to meet with monkeypox patients, avoid close contacts such as touching the body, having sex with suspected infected person and sharing daily necessities. Take personal protection when caring for or visiting patients. Wash hands under running water with soap or hand sanitizer.
2. People who have recently returned to China or will return soon should monitor their health. Those who have contacted or been exposed to suspected animal or human monkeypox cases in overseas countries should consult local disease control and prevention institutions. If you have symptoms of fever and rash, please seek medical treatment and tell the doctor about your overseas travel history. In addition to the abovementioned precautions, those who are about to return to China should make their health declaration at the customs.
3. People who plan to go abroad in the near future should closely follow the monkeypox epidemic in the destination country and learn about methods of monkeypox prevention and control, such as avoiding contact with rodents and monkeypox patients and sharing items with patients.
4. The general population of the country should note that China has not found the monkeypox virus in wild animals or during entry quarantine inspections. There is no immediate risk of infection in the general population, but if imported monkeypox cases are found, people in contact with them are at risk of infection.
Infection control in medical institutions
When medical staff treat patients with rashes who have a travel history in countries that have reported monkeypox cases, they should consider the possibility of monkeypox infection. When treating suspected or confirmed patients, medical staff should take protective measures such as wearing disposable latex gloves, medical protective masks and goggles, and washing their hands conscientiously. Taking samples from suspected patients should be carried out by trained personnel. Patient samples should be transported in safe packaging. The environment and items that may be contaminated should be sterilized rigorously.
It is recommended not to import rodents or primates unless necessary and to enhance quarantine inspection of imported and sent animals.